Portable display

ABSTRACT

In one embodiment, the modular display includes aggregates of individual panel tiles arranged between two large plastic sheets. The footprint of the large plastic sheet sandwich becomes the dimension of the display screen. The tilettes are phosphor emission panels with a full complement of emittable pixels. By separating the tilettes from the final full dimension sheet, the tilettes can be manufactured in transportable sizes and the outer full dimension sheets can be rolled for easy transport to the final install location.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of co-pending U.S. patentapplication Ser. No. 13/735,407, filed on Jan. 7, 2013, which claimsbenefit of U.S. Provisional Patent Application Ser. No. 61/584,133,filed Jan. 6, 2012 which is herein incorporated by reference in itsentirety.

BACKGROUND

Field paw Embodiments of the present invention generally relate to aportable display. More particularly, embodiments of the invention relateto a modular portable display.

Description of the Related Art

There are two main ways to make larger displays. One way is to make thecurrent technologies in larger footprints. As an example an LCD displaycan be made larger with a larger glass and appropriate manufacturing touse the larger glass for building the larger LCD arrays. However, thelarger glass is more expensive to manufacture, heavier to handle, morefragile and becomes more difficult to maneuver in tighter passagewayswhen bringing the larger display to its final destination.

The other main display technology is tile based, which permits easytransport as each tile can be uniquely transported, then arranged in anarray to produce a large screen display. Here the problem is that thegaps between the tiles are noticed creating a visual image gap betweeneach tile.

SUMMARY

Embodiments of the present invention generally relate to a modular tiledisplay system that is not only portable, but when assembled results ina seamless large display.

In one embodiment, the modular display includes aggregates of individualpanel tiles or “tilettes” arranged between two continuous outer visiblelight transparent containment sheets. The footprint of the continuousouter containment sheet sandwich becomes the dimension of the displayscreen. The tilettes are phosphor image emission modules with a fullcomplement of emittable pixels. By separating the tilettes from thefinal full dimension outer containment sheet, the tilettes can bemanufactured in transportable sizes and the outer full dimensioncontainment sheets can be rolled for easy transport to the final installlocation.

In one embodiment, an apparatus is provided. The apparatus comprises aplurality of image emission modules each comprising multiple phosphorregions, wherein at least one phosphor region emits light of a firstcolor when excited and at least one phosphor region emits light of asecond color when excited and a visible light transparent supportstructure comprising a first visible light transparent sheet and asecond visible light transparent sheet, wherein the plurality of imageemission modules are placed in between the first and second visiblesheets and the apparatus has a continuous concave bend.

In another embodiment, an apparatus is provided. The apparatus comprisesa plurality of image emission modules each comprising multiple phosphorregions, wherein at least one phosphor region emits light of a firstcolor when excited, and at least one alternate phosphor region emitslight of a second color when excited and a visible light transparentsupport structure comprising a first visible light transparent sheet anda second visible light transparent sheet, wherein the plurality of imageemission modules are positioned adjacent to each other between the firstvisible light transparent sheet and the second visible light transparentsheet, and wherein the center of the adjacent positioned plurality ofimage emission modules and the center of the first and second visibletransparent sheets are substantially centered to each other.

In yet another embodiment, a method for making a portable display screenis provided. The method comprises positioning a plurality of imageemission modules on a first visible light transparent sheet, wherein theplurality of image emission modules comprise multiple phosphor regions,wherein at least one phosphor region emits light of a first color whenexcited and at least one phosphor region emits light of a second colorwhen excited, positioning a second visible light transparent sheet overthe plurality of image emission modules and the first visible lighttransparent sheet to form a sandwich structure, and simultaneouslybending the sandwich structure such that the bowed visible lighttransparent sheets apply a normal load to the plurality of imageemission modules.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 illustrates a perspective schematic diagram of one embodiment ofa display system according to embodiments described herein;

FIG. 2 illustrates a partial cross-sectional view of the display systemtaken at section A-A of FIG. 1 according to embodiments describedherein;

FIG. 3 illustrates a schematic view of one embodiment of the displaysystem of FIG. 1 with a visible light transparent sheet removedaccording to embodiments described herein;

FIG. 4 illustrates a partial cross-sectional view of one embodiment of adisplay system according to embodiments described herein;

FIGS. 5A-5D illustrate various side views of one embodiment of an imageemission module according to embodiments described herein;

FIG. 6 illustrates a perspective of another embodiment of a displaysystem according to embodiments described herein; and

FIG. 7 illustrates an exploded schematic view of another embodiment of adisplay system according to embodiments described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

Embodiments of the present invention relate to a modular display that islight weight and flexible enough to be brought into smaller passagewayssuch as doorways. The modular display may be assembled into a largedisplay with the same resolution as displays of smaller sizes.

In one embodiment, the modular display includes tilettes insertedbetween two visible light transparent sheets that are either bent toabout 5 degrees to hold the tile panels in place. In certainembodiments, the visible light transparent sheets may be clampedtogether. Distinct phosphor tilettes of a common polymer coefficient ofthermal expansion (“CTE”) are arranged within a single polymer sandwichto provide a true seamless large and transportable display. The phosphortilettes may be arranged to abut against each other such that theabutment causes the spacing between adjacent tilettes to be on the orderof the pixel pitch thus there appears to be no seam gap between phosphortilettes.

In one embodiment, the modular display includes an array of individualpanel tiles or “tilettes” arranged between two continuous outer visiblelight transparent containment sheets. The footprint of the continuousouter containment sheet sandwich becomes the outer dimension of thedisplay screen. The footprint of the continuous outer containment sheetmay be as large as the outer dimension of the array of individualtilettes or larger than the outer dimension of the array of individualtilettes. The tilettes are phosphor image emission modules with a fullcomplement of emittable pixels. By separating the tilettes from thefinal full dimension visible light transparent outer containment sheet,the tilettes can be manufactured in transportable sizes and the outerfull dimension visible light transparent containment sheets can berolled (and being plastic are light weight) for easy transport to thefinal install location.

As used herein, the terms “tilette,” “panelette,” “panel stack,” “paneltiles,” an image emission module may refer to the individualservo/phosphor/contrast layer panels, which can be placed togetherside-by-side to create a large panel tilette array. Tilettes may becomposed of the standard layers of a Laser Phosphor Display panel. Thetilettes may include a Fresnel lens layer which normalizes the angledincident excitation beams to the panel; a servo layer, which inconjunction with the servo beam permits the detected reflected beam toguide positioning and timing information to the excitation drivers andbeam positioners; a co-extruded dichroic filter layer, which passesexcitation light and reflects visible light; a phosphor layer, which hasa repeating structure of distinct colored light emitting phosphors; astandoff layer, which physically separates the phosphor layer from thenext layer; a color filter layer, which permits only the intended lightto the pass from the phosphor layer to the viewer; and a UV block layerthat filters any remaining excitation light from passing through to theviewer. The tilette array may be held together in a manner describedbelow and as a whole may be attached to a framing structure, which alsoholds the light engines.

FIG. 1 is a perspective schematic diagram of a display system 100,according to embodiments of the invention. The display system 100 is alight-based electronic display device configured to produce video andstatic images for a viewer 110 using light-emitting phosphors. Forexample, the display system 100 may be a laser-phosphor display (LPD), alight-emitting diode (LED) digital light processing (DLP), or otherphosphor-based display device. As depicted in FIG. 1, the display system100 comprises a plurality of image emission modules 120 a-d that form animage mission module array and a visible light transparent supportstructure 130 for supporting the plurality of image emission modules 120a-d that are arranged to form a single tiled display screen. The visiblelight transparent support structure 130 comprises a first visible lighttransparent sheet 140 and a second visible light transparent sheet 150.It should be noted that although four image emission modules 120 a-d(hereinafter 120) are depicted in FIG. 1, any plurality of imageemission modules may be used with the embodiments described herein.

Each image emission module 120 has a display screen 122 with phosphorregions 124 that may be phosphor stripes, phosphor dots or otherarrangements of the phosphors. The display system 100 further comprisesa light engine 160 that is used to produce one or more scanning laserbeams 162 to excite the phosphor material on the screen 122. The lightengine 160 may include multiple laser beams selected from the groupconsisting of one or more of an excitation lasers, one or more servofeedback lasers, and combinations thereof. The lasers may be configuredwith appropriate focus and scanning mechanisms and optics. The lightengine 160 is typically arranged to associate with a corresponding imageemission module. Although a single light engine 160 is shown, generallythere is one light engine per image emission module, though it ispossible for a single light engine to excite more than one imageemission module, for example, the associated image emission module andone or more adjacent image emission modules.

The phosphor regions 124 are made up of alternating phosphor regions ofdifferent colors, e.g., red, green, and blue, where the colors areselected so that they can be combined to form white light and othercolors of light. The scanning laser beam 162 is a modulated light beamthat includes optical pulses that carry image information and is scannedacross screen 122 along two orthogonal directions, e.g., horizontally(parallel to arrow 164) and vertically (parallel to arrow 166), in araster scanning pattern to produce an image on the screen 122 for theviewer 110. In some embodiments, the modulated light beam is caused bymodulating the laser directly in one or both of pulse code or pulsewidth modulations. In some embodiments, the scanning laser beam 162includes visible lasers beams of different colors that discretelyilluminate individual pixel elements of the screen 122 to produce animage. In other embodiments, the scanning laser beam includes invisiblelaser beams, such as near-violet or ultra-violet (UV) laser beams thatact as excitation beams to excite phosphors on the screen. In suchembodiments, the scanning laser beam 162 is directed to discrete pixelelements that are formed from phosphor regions 124 or to portions of thephosphor regions 124 that act as discrete pixel elements and are made upof light-emitting material that absorbs optical energy from the scanninglaser beam 162 to emit visible light and produce an image.Alternatively, the scanning laser beam 162 comprises hybrid visible andinvisible lasers. For example, a blue laser can be used to generate bluecolor on screen 122, and the same blue laser could be used to excitephosphors that emit red and green light when excited. Alternatively, aUV laser may be used to excite phosphors that emit green light whenexcited, and a red and blue laser may be used to produce red and bluecolor directly on the screen 122.

The visible light transparent support structure 130 comprises a firstvisible light transparent sheet 140 and a second transparent visiblelight transparent sheet 150. As depicted in FIG. 1, the first visiblelight transparent sheet 140 and the second visible light transparentsheet 150 are positioned on opposite sides of the image emission modules120 a-120 d holding the image emission module array together between thetwo sheets 140, 150. The first visible light transparent sheet 140 andthe second visible light transparent sheet 150 may comprise sheets thatare of a relatively stiff material. The first visible light transparentsheet 140 and the second visible light transparent sheet 150 may belarger in length and width than the image emission module array. Thesheets 140, 150 may be bolted together, bonded together, clampedtogether and/or held together using a slight pressure from the sideswhich may cause the sheets to bow.

The first visible light transparent sheet 140 and the second visiblelight transparent sheet 150 may comprise any material having suitableoptical clarity, rigidity, toughness, and UV yellowing resistance. Thematerial should also have the suitable stiffness, creep resistance (i.e.slow deformation under constant load), CTE, low anisotropy, and lowcoefficient of humidity expansion. In certain embodiments, thecoefficient of friction may be a factor. In certain embodiments, thefirst visible light transparent sheet 140 and the second visible lighttransparent sheet 150 each comprise acrylic sheets, e.g., Plexiglas. Incertain embodiments, the first visible light transparent sheet 140 andthe second visible light transparent sheet 150 are each independentlyselected from materials comprising polyethylene terephthalate (PET),polyethylene naphthalate (PEN), polyolefins, polyamide,poly(oxymethylene) (POM), poly(methyl methacrylate) (PMMA),polycarbonate and combinations thereof. The first visible lighttransparent sheet 140 and the second visible light transparent sheet 150may each have a thickness independently selected from about 1.0millimeter to about 6.0 millimeters. The first visible light transparentsheet 140 may have a thickness from about 1.5 millimeters to about 3.0millimeters, the second visible light transparent sheet 150 has athickness from about 4.5 millimeters to about 6.0 millimeters.

FIG. 2 illustrates a partial cross-sectional view of the display system100 taken at section A-A of FIG. 1. FIG. 2 illustrates two separateimage emission modules 120 c, 120 d or “tilettes” with a tilette gap 202defined in between the two image emission modules 120 c, 120 d. Eachimage emission module may include an optional color filter layer 210,phosphor regions 124 mounted on a thin transparent substrate 240, andstandoff dividers 220. The color filter layer 210 is positioned on theside of screen 122 facing the viewer 110, the transparent substrate 240is positioned on the opposite side of the screen 122, and the phosphorregions 124 are disposed between the color filter layer 210 and thetransparent substrate 240 as shown.

Color filter layer 210 may be a thin substrate, such as a 1 mmsubstrate, and may be configured with filter elements 210R, 210G, and210B that each transmit light of one particular color. The substrate maybe a plastic or glass. In some embodiments, the color filter layer 210is a structurally rigid or semi-rigid plate, and in other embodiments,color filter layer 210 is a relatively flexible substrate or sheet thatis held in place by other structural elements of screen 122. In theembodiment illustrated in FIG. 2, color filter layer 210 includes red,green, and blue filter elements, which are positioned to align with acorresponding red, green, or blue phosphor regions 124, denoted by R, G,and B, respectively. The filter elements 210R, 210G, and 210B may beformed with a lithographic process on the requisite portions of thecolor filter layer 210 prior to the assembly of screen 122. In theembodiment illustrated in FIG. 2, the filter elements 210R, 210G, and210B are configured as elongated strips (perpendicular to page) that,like the phosphor regions 124 and the standoff dividers 220, extendvertically across screen 122, i.e., parallel to arrow 166 in FIG. 1.

The standoff dividers 220 separate the phosphor regions 124 from eachother and prevent the color filter layer 210 from touching the phosphorregions 124. Thus, the standoff dividers 220 form a gap 260 around eachof the phosphor regions 124. One example material for the standoffdividers 220 is a photosensitive resin. The photosensitive resin may beapplied as an imageable photo-resist laminate to a substrate, such asthe color filter layer 210 or other planar structural member, andselectively exposed to the requisite light energy, such as UV light.When patterned appropriately, the standoff dividers 220 can be formed inthe desired regions on the substrate and the remainder of thephoto-resist laminate removed. As shown, the standoff dividers 220 maybe formed to have walls that are angled, i.e., not normal to thetransparent substrate 240 or the color filter layer 210. In someembodiments, the standoff dividers 220 are configured as elongatedstrips positioned between the phosphor regions 124. In one embodiment,the standoff dividers 220 have a height of between about 50 and 100 μm.

The phosphor regions 124 are configured to emit light of one color whenexcited by an excitation beam, such as the scanning laser beam 162.Thus, each pixel element of the screen 122 may include one or morephosphor regions 124, where each phosphor region 124 acts as a subpixelof a larger pixel element. In the embodiment illustrated in FIG. 2, onedimension of a pixel element, i.e., pixel width, is defined by the widthof three phosphor regions 124, and the orthogonal dimension, i.e., outof the page, or vertical, is defined by the excitation laser beam spotsize. In such an embodiment, where the phosphor regions 124 arecontinuous stripes, the vertical position of each pixel element is notfixed and may be selected as desired by adjusting the vertical positionat which the excitation laser beam is directed to each phosphor region124. In other embodiments, the standoff dividers 220 may define bothdimensions of each phosphor region 124, so that phosphor regions 124 areseparated on all sides from adjacent phosphor regions by the standoffdividers 220 formed in a grid pattern. In one embodiment, each of thephosphor regions 124 is spaced at a pitch of 500 μm to 550 μm, so thatthe pixel width of a pixel element on screen 122 is on the order ofabout 1500 μm. In other embodiments, each of the phosphor regions 124 isspaced at a pitch of about 180 μm to 220 μm, so that the pixel width ofa pixel element on screen 122 is on the order of about 600 μm. In yetother embodiments, the pixel elements of the screen 122 may includeseparate phosphor regions rather than portions of phosphor regions 124.For example, each subpixel may be a discrete and isolated phosphor dotor rectangle of one particular light-emitting phosphor material.

The transparent substrate 240 is a thin, semi-rigid material that istransparent to UV and visible light and has an index of refraction thatis relatively close to that of the phosphor regions 124. Because theindex of refraction of transparent substrate 240 is selected to beapproximately equal to the index of refraction of the phosphor regions124, the transparent substrate 240 and the phosphor regions 124 areoptically coupled, and light leaving the phosphor regions 124 passesinto the transparent substrate 240 rather than reflects off theinterface between the transparent substrate 240 and the phosphor regions124. Other desirable characteristics for the transparent substrate 240include having a low coefficient of thermal expansion and low moistureabsorption, and being readily manufacturable in thin layers. Inaddition, the transparent substrate 240 is preferably comprised of amaterial that is not brittle and does not break-down with exposure to UVlight and discolor over the lifetime of the display system 100. In someembodiments, the transparent substrate 240 comprises a polyethyleneterephthalate (PET) film, which largely satisfies the aboverequirements. In one embodiment, the transparent substrate 240 comprisesa PET film that is six microns or less in thickness.

The light engine 160 (shown in FIG. 1) forms an image on the screen 122by directing the scanning laser beam 162 to the phosphor regions 124 andmodulating the scanning laser beam 162 to deliver a desired amount ofoptical energy to each phosphor region 124 of the screen 122. Eachphosphor region 124 outputs light for forming a desired image by theemission of visible light created by the selective laser excitationthereof by the scanning laser beam 162. Some of the light emitted by thephosphor region 124 will be incident on the standoff dividers 220, whichmay absorb and/or transmit said light, depending on the material fromwhich the standoff dividers 220 are formed and the angle of incidence ofthe light with respect to the surfaces of the standoff dividers 220.Transmission of incident light from the phosphor region 124 into anadjacent phosphor region allows colors from different phosphor regionsto mix, thereby degrading color purity of the image, while absorption ofsuch light reduces the amount of light that ultimately reaches theviewer 110. Embodiments of the invention contemplate the use of amaterial having a low-index of refraction that is disposed in the gap260 between the phosphor regions 124 and the standoff dividers 220. Thepresence of the low-index material in gap 260 minimizes the absorptionand/or transmission by the standoff dividers 220 of light emitted by thephosphor regions 124, thereby allowing more of the light emitted by thephosphor regions 124 to propagate through the color filter layer 210 andreach the viewer 110.

In another embodiment, the screen 122 may include an opticalcompensation element to control the angle of incidence of the incomingbeam 162. Optical compensation elements include various optical devicesthat can adjust the direction of the received light, such as layeredwaveguides, prisms, lenses or other similar devices that can throughtheir geometric shape and/or material properties (e.g., index ofrefraction) adjust the angle of the light passing there through. In oneembodiment, the optical compensation element comprises a Fresnel lenslayer 270. A Fresnel lens reduces the amount of material requiredcompared to other optical compensation means, such as a conventionalspherical lens, by breaking the lens into a set of concentric annularsections known as Fresnel zones. In each zone, the overall thickness ofthe lens is decreased, effectively separating the continuous surface ofa standard lens into a set of surfaces of the same curvature. A Fresnellens allows a substantial reduction in thickness, weight, and volume ofmaterial when compared to an equivalent spherical lens. Thus, Fresnellens layer 270 enables control of the angle of incidence of incomingbeam 162 on the phosphor regions 124 without the thickness and weightassociated with a convention spherical lens system. In one embodiment,Fresnel lens layer 270 is configured to direct incoming beam 162 ontothe phosphor regions 124 with a normal or near-normal angle ofincidence. It should be noted that the location of the Fresnel lenslayer 270 as shown in FIG. 2 is not intended to be limiting as to thescope of the invention, since the Fresnel lens layer 270 could also bepositioned on one or more surfaces in the image emission module 120without deviating from the basic scope of the invention disclosedherein.

In one embodiment, the Fresnel lens layer 270 may be plastic, so it maybend to hold in place the tilettes by bending the outer shell plasticsheets. Additionally, the Fresnel lens layer 270 may be flexible.

In another embodiment, the Fresnel lens layer 270 may be glass and flat,so the final display sandwich cannot be bent to hold the tilettes inplace. Alternatively, the bend could be so gradual that the segments ofthe flat Fresnel lens layer 270 can mate with the slightly curved paneland function as if both are planar.

In yet another embodiment, the Fresnel lens layer 270 may be a glassthat is so thin, that a slight bend is permissible. This thin glassFresnel lens may be used in a monolithic panel. In certain embodimentswhere there is no panel frame structure for intermediate tiles, theFresnel lens layer 270 can be positioned close to the panel stack asopposed to designs where thick glass separates the Fresnel lens layerfrom the panel stack so that the panel frame edges don't block theextreme rays from reaching the panel edges.

The Fresnel lens layer 270 may be the same dimension of as each of theimage emission modules or “tilettes”; hence multiple tilettes may bepaired with corresponding Fresnel lenses. In another embodiment, theFresnel lens layer 270 may be sized to the size of two or more tilettesand possibly the size of a whole tilette array.

In one embodiment the Fresnel lens layer 270 may have a PET backing andthe tilettes may comprise PET material as well.

In certain embodiments, the screen 122 may further comprises a reflectorlayer (not shown), such as a glass substrate, that acts as a structurallayer of screen 122, reflects visible and UV light toward phosphorregions 124 and viewer 110, and is spaced from the transparent substrate240 to define a low-index gap. In one embodiment, reflector material isa very thin, co-extruded film. More specifically, multiple sheets offilms with different refractive indices may be laminated or fusedtogether to construct a composite sheet as a dichroic layer. Exemplaryfilms including a polymeric and non-polymeric material are disclosed inU.S. Pat. Nos. 6,010,751 and 6,172,810 which are incorporated byreference in their entirety as part of the specification of thisapplication. In particular, coextruded multilayer interference filtersas taught in U.S. Pat. No. 6,531,230 can provide precise wavelengthselection as well as large area in a very thin cost effectivemanufacturing composite layer set. The entire disclosure of U.S. Pat.No. 6,531,230 is incorporated by reference as part of the specificationof this application.

FIG. 3 illustrates a schematic view of one embodiment of the displaysystem 100 of FIG. 1 with a visible light transparent sheet removed. Thedisplay system 100 depicted in FIG. 3 shows a 2×2 arrangement of imageemission modules 120 a-120 d positioned on the second visible lighttransparent sheet 150 prior to placement of the first visible lighttransparent sheet 140 over the image emission modules 120 a-120 d. Theplurality of image emission modules 120 a-d may be positioned adjacentto each other and the center of the adjacent positioned plurality ofimage emission modules and the center of the first visible lighttransparent sheet 140 and the second visible light transparent sheet 150may be substantially centered to each other. The first visible lighttransparent sheet 140 and the second visible light transparent sheet 150may each be of a size greater than an aggregate of the plurality ofadjacent image emission modules 120 a-d such that the aggregate of theplurality of adjacent image emission modules are within the perimeterboundaries of the first visible light transparent sheet 140 and thesecond visible light transparent sheet 150.

FIG. 4 illustrates a partial cross-sectional view of one embodiment of adisplay system according to embodiments described herein. As depicted inFIG. 4, the display system is bent to have a continuous concave bendthus holding the image emission modules in place. The first visiblelight transparent sheet 140 and the second visible light transparentsheet 150 are bowed with the first visible light transparent sheet 140held in tension as shown by arrows 402 and the second visible lighttransparent sheet 150 held in compression as shown by arrows 404. As thefirst visible light transparent sheet 140 is held in tension and thesecond visible light transparent sheet 150 is held in compression anormal load is applied to the image emission modules. In one embodiment,the first visible light transparent sheet 140 and the second visiblelight transparent sheet 150 are bent to between about 1 degree and about10 degrees to hold the image emission modules in place. In anotherembodiment, the first visible light transparent sheet 140 and the secondvisible light transparent sheet 150 are bent to between about 1 degreeand about 5 degrees to hold the image emission modules in place.

Several techniques are contemplated for aligning/attaching non-laminatedlayer tilettes to the outer acrylic sheets. For example, the tilettesare cut to size with a glass template. In another example, a laser maybe used to cut the exact tilette size with vision assist. In yet anotherexample, a mechanical cutting knife may be used to cut the tilette size.The tilettes are then aligned to each other and arrayed in a manner thata side of one tilette abuts an adjacent tilette side.

Several techniques are contemplated to provide uniform tension on thepressed outer layers. In one embodiment, a stiff backing layer is heldin a curved track top and bottom and compressed from the edges inward tostiffen the backing plate. Thinner PET based tilettes and outer acrylicsheet layers are pulled around the curved shape to generate compressionin of the layers. In another embodiment, the layers are arranged sotension is used in both the backing layer and top layer to accomplishthe same goal.

Several characteristics are considered for materials for the outer andinner layers. The material should have the suitable optical clarity,rigidity, toughness, and UV yellowing resistance. The material shouldalso have the suitable stiffness, creep resistance (i.e. slowdeformation under constant load), CTE, low anisotropy, low coefficientof humidity expansion. In some instances, the coefficient of frictionmay be a factor. For example, in one embodiment, the two outer layersallow some “float,” so that the “tilettes” do not tear apart withtemp/RH cycling.

Several configuration of the phosphor in context of edges of each paneltilettes are contemplated. In one embodiment, the phosphor sheet isflush to all edges. In another embodiment, the overlap of phosphor intothe tilette gap. In yet another embodiment, the “tilette” is defined asa subset size of the full display, but including being equal in size tothe whole display footprint (i.e. the case where the ribsheet is thefull size, and the phosphor (or phosphor/CF) zip into one monolithicsheet (i.e. seams not through all layers). In yet another embodiment, aconfiguration where seams are staggered, so that the rib sheet andphosphor/CF deliberately do not align (i.e. like brick laying pattern).In yet another embodiment, a configuration of the tilettes are either ofdifferent sizes and different spatial arrangement in relation to eachother between the sheets 140 and 150 is anticipated.

FIGS. 5A-5D illustrate various side views of one embodiment of an imageemission module 120 according to embodiments described herein before thebending of the outer sheets. Each image emission module 120 has foursides. Two of the sides 502, 504 are ends where the phosphor regions 124cross sections end (at the edge). The third side 506 is a continuousdivider side which separates the phosphor regions 124 from each other,and the last side 508 is a continuous strip of phosphor. The imageemission modules 120 may be arranged adjacent to each other such thatthe stripe cross section side is adjacent to another image emissionmodule's stripe cross section side; the image emission module's dividerside is adjacent to another image emission module's continuous phosphorstripe side; and the continuous stripe side is adjacent to another imageemission module's continuous divider side. It is contemplated that asmany image emission modules as needed may be placed adjacent to eachother with no limit.

FIG. 6 illustrates a perspective of another embodiment of a displaysystem 600 according to embodiments described herein. As depicted inFIG. 6, the display system 600 comprises six image emission modules 120a-f and a first visible light transparent sheet 140 for supporting theplurality of image emission modules 120 a-d that are arranged to form asingle tiled display screen.

FIG. 7 illustrates an exploded schematic view of another embodiment of adisplay system 700 according to embodiments described herein. Thedisplay system 700 comprises two outer visible light transparent sheets140, 150 and two inner visible light transparent sheets 702, 704. Theouter visible light transparent sheets 140, 150 may be acrylic sheetsand the inner visible light transparent sheets 702, 704 may be PETsheets. The two outer visible light transparent sheets 140, 150 are thesame size, but smaller than the two inner visible light transparentsheets 702, 704, but the two outer visible light transparent sheets 140,150 are wider/longer than the tilette array layer.

One technique to hold the panelettes in place is there are four pointsthat locate the panel stack in x and y such that expansion andcontraction occurs from those points out to the edge of the panel. Thisminimizes the total CTE movement of the panel stack. The clamping isdone by the two pieces of acrylic that the panel stack is sandwichedbetween. When the acrylic pieces are bowed, and one held in tension andthe other in compression, it applies a normal load to the panel stack.The panel stack may include two layers, each on a monolithic piece ofPET. One is the Fresnel layer (Fresnel lenses, no glass) tiled on alarge sheet of PET. The other layer is a large sheet of PET with tiledPET color filter/RGB phosphor/PET servo assemblies.

In one embodiment, the tilette array may have a large PET sheet oneither side of the tilette array, wherein the two PET sheets are largerand, hence extend beyond the tilette Fresnel lens array.

In one embodiment, two acrylic sheets may comprise sheets that are of arelatively stiff material and are larger in length and width than thetilette array. The acrylic sheets are located on either side of thetilette array and clamped, thereby holding the tilette array togetherbetween the two acrylic sheets. The sheets may be bolted together,clamped together or held together using a slight pressure from thesides, which may cause the acrylic sheets to bow. The bowing willuniformly hold the tilette array in placed.

In one embodiment, two PET sheets may comprise sheets that are ofessentially the same material as the tilette array material and whichare larger in length and width than the tilette array. The two PETsheets are located on either side of the tilette array and clamped,thereby holding the tilette array together between the two PET sheets.The PET sheets may be pinned together or clamped together.

Two acrylic sheets may be disposed on either side of the two PET sheets,which in turn, are located on either side of the tilette array PETsheets sandwich and clamped, thereby holding the tilette array PETsheets sandwich together between the two acrylic sheets. The acrylicsheets may be of a relatively stiff material and larger in length andwidth than the tilette array, but smaller in length and width than thePET sheets. The acrylic sheets may be bolted together, clamped together,or held together with a slight pressure from the sides, which may causethe acrylic sheets to bow. The bowing will uniformly hold the tilettearray PET sheets sandwich in place.

In one embodiment, the CTE of outer acrylic sheets match at around theinner PET sheets' value of 15-17 ppm/deg C. along the web and cross-webdirections. In another embodiment, the outer skins CTE are matched butdifferent from the tilettes, whereby the tilettes are allowed to floatwithin the support acrylic skins.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. An apparatus comprising: a plurality of image emission modules eachcomprising: multiple phosphor regions, wherein at least one phosphorregion emits light of a first color when excited and at least onephosphor region emits light of a second color when excited; a pluralityof light engines, wherein each light engine generates one or moreexcitation beams to excite the multiple phosphor regions of acorresponding image emission module and the multiple phosphor regions ofone or more image emission modules adjacent to the corresponding imageemission module; and a visible light transparent support structurecomprising: a first visible light transparent sheet wherein theplurality of image emission modules are placed upon the first visiblelight transparent sheet.
 2. The apparatus of claim 1, wherein the firstvisible light transparent sheet is bowed.
 3. The apparatus of claim 2,wherein the first visible light transparent sheet is held in compressionto form a continuous concave bend.
 4. The apparatus of claim 2, whereinthe first visible light transparent sheet is held in tension to form acontinuous concave bend.
 5. The apparatus of claim 2, wherein the bowedfirst visible light transparent sheet applies a normal load to theplurality of image emission modules.
 6. The apparatus of claim 2,wherein the plurality of image emission modules are positioned adjacentto each other and the center of the adjacent positioned plurality ofimage emission modules and a center of the first visible lighttransparent sheet are substantially centered to each other.
 7. Theapparatus of claim 6, wherein the first visible light transparent sheetis of a size greater than an aggregate of the plurality of adjacentimage emission modules such that the aggregate of the plurality ofadjacent image emission modules are within a perimeter boundary of thefirst visible light transparent sheet.
 8. The apparatus of claim 7,wherein the plurality of image emission modules further comprise a firsttransparent substrate on which the multiple phosphor regions aremounted.
 9. The apparatus of claim 8, wherein the plurality of imageemission modules further comprise a second transparent substrateconfigured with color filter elements.
 10. The apparatus of claim 9,wherein the plurality of image emission modules further comprise dividermembers that separate the multiple phosphor regions, and the dividermembers have walls that are angled with respect to a transparentsubstrate to which the multiple phosphor regions are mounted.
 11. Theapparatus of claim 1, wherein the plurality of image emission modulesare positioned adjacent to each other and the center of the adjacentpositioned plurality of image emission modules and a center of the firstvisible light transparent sheet are substantially centered to eachother.
 12. The apparatus of claim 11, wherein the first visible lighttransparent sheet is of a size greater than an aggregate of theplurality of adjacent image emission modules such that the aggregate ofthe plurality of adjacent image emission modules are within a perimeterboundary of the first visible light transparent sheet.
 13. The apparatusof claim 1, wherein the plurality of image emission modules furthercomprises a coextruded dichroic layer that passes excitation light in afirst direction and filters visible light in a second direction.
 14. Theapparatus of claim 1, wherein the first visible light transparent sheetis selected from materials comprising poly(methyl methacrylate) (PMMA)and polycarbonate acrylic.
 15. The apparatus of claim 1, wherein thefirst visible light transparent sheet has a thickness selected fromabout 1.0 millimeter to about 6.0 millimeters.
 16. The apparatus ofclaim 15, wherein the first visible light transparent sheet has athickness from about 1.5 millimeters to about 3.0 millimeters.
 17. Theapparatus of claim 1, wherein a concave bend has an angle of about fivedegrees or less.
 18. The apparatus of claim 1, wherein the plurality ofimage emission modules further comprise a first transparent substrate onwhich the multiple phosphor regions are mounted.
 19. The apparatus ofclaim 18, wherein the plurality of image emission modules furthercomprise a second transparent substrate configured with color filterelements.
 20. The apparatus of claim 19, wherein the plurality of imageemission modules further comprise divider members that separate themultiple phosphor regions, and the divider members have walls that areangled with respect to a transparent substrate to which the multiplephosphor regions are mounted.